Controller for electric motors



Feb 3, 1931. N. L. MORTENSEN L Q CONTROLLER FOR ELECTRIC MOTORS I Filed Dec. 10, 192'? 2 Sheets-Sheet l I INVENTOR.

M 1. 31mm BY A TTORNEYS.

, 1927 2 Sheets-Shea? 2 N. L. MQRTENSEN CONTROLLER FOR ELECTRIC MOTORS Filed DEC. 10

Feb 3, 1931.

- INVENTOR.

. ATTORNEYS.

Patented Feb. 3, 1931 UNITED STATES PATENT o Fic NIELS L. MORTENSEN, OF WHITE-FISH BAY, WISCONSIN, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO CUTLER-HAMMER, 1NC.,'A CORPORATION OF DELAWARE CONTROLLER FOR ELECTRIC MOTORS Application filed December 10, 1927. Serial No. 239,146.

This invention relates to controllers for electric motors, and while not limited thereto is particularly applicable to Controllers for blast furnace tops.

Blast furnace tops are ordinarily provided with a hopper for receiving material supplied the furnace. The hopper is rotatable to provide for distribution of the material and the -same is usually provided with automatic control means which provides for dumping of a fixed number of loads of material at given points into the furnace. However, in practice it has been found'desirable to provide for variation'of the number of loads of material dumped at given points into the furnace and the present invention has among its objects to provide a controller for this purpose.

Another object is to provide an automatic controller of the aforesaid character including a control part adapted to be set in different positions for selection of the number of loads to be dumped into the furnace at predetermined points.

Another object is to provide an automatic controller of the aforesaid character which understood that various changes may be made 'in the embodiment illustrated without departing from the spirit and scope of the appended claims.

In the drawing, Figure 1 illustrates schematically and diagrannnatically a furnace top controller constructed in accordance with the invention,

Fig. 2 is an across-the-line diagram of thecontrol circuits illustrated in Fig. 1, and

Fig. 3ris a diagrammatic View of one type of furnace top to which the controller shown in Fig. 1 may be applied.

The reference character M designates a direct current motor for operating the hopper of a blast furnace top of the character shown in Fig. 3. The blast furnace top shown in this figure includes a large bell B and a small bell B each of which is adapted to be opened terial therein directly above such points and then emptying the hopper by opening the small bell B As hereinafter set forth, the

controller illustrated is designed to deposit a ,selected number of loads of material at six equally spaced points on the large bell B.

Motor M as shown in Fig. 1 is provided with an armature A, a series field F, and a shunt field, F and the same is provided with a well known type of controller including a pair of electromagnetically operated line switches 1 and 2 and a pair of electromagnetically operated accelerating switches 3 and 4: for controlling resistances R and R in the armature circuit. Switches 3 and 4 are of like construction, each of the same being provided with a contact member pivoted intermediate its ends, and a pair of series operating wind ings arranged on opposite sides of such pivot. As is well known, during startin of the motor the lower windings of switc es 3 and 4 prevent closure thereof under the action of the upper-windings until given current conditions exist in the motor circuit.

The line switches 1 and 2 are controlled by an electromagnetically operated timing relay 10 which is under the control of a pair of electromagnetically operated relays 11 and 12. Timing relay 10 is normally open and closing movement thereof is retarded 4 by a dash pot' 10 Relay 12, in additionto its aforementioned function, acts through the medium of a pair of switches 13 and 14 to control an electromagnetically operated switch 15. The switch 15 which will be hereinafter termed the load switch is adapted to operate in a. step by step manner upon dumping of successive'loads into the distributing hopper. Relay 12- is controlled by relay 11 and by electromagnetically operated switches 16 and 17. Switch 16 which will be hereinafter termed the position switch is controlled by the load switch 15 through adapted to operate in astep by step manner and is under the control of a rotary switch 19. Switch 19 is connected through suitable gearing with the distributing hopper H and it is assumed that said switch makes one complete revolution upon rotation of the hopper H through an angle of V 60 degrees. I

The controller also includes a three polo double throw switch 22 which is adapted as hereinafter set forth to commutate certain of the control connections to provide for single or double bucket operation of the controller. 7

The construction and operation of certain of the aforementioned control instrumentalities will now be more fully described. Relay 11 is provided with an operating winding 11, a pair of normally closed-down contacts 11 and a. pair of normally open up contacts 11. Relay 11 is adapted to be held in its attracted position by a latching mechanism having a tripping winding 11 and for purposes hereinafter set forth the same is provided with normally closed auxiliary contacts 11, and normally open auxiliary contacts 11. Relay 12 is similar to the relay 11 and the several parts thereof are designated by exponents corresponding to those used in the fore oing description of relay 11.

e control switches 13 and 14 which as before'stated control the load switch 15 are normally open and as hereinafter set forth the same are controlled by the skip hoist which furnishes material to the blast furnace top. Control of said switches may be effected in any suitable or well known manner, as by means of a nut 25 which is movable by a screw 26 operatively connected to the skip hoist operating mechanism as shown in Fig. 3.

The load switch 15 hereinbefore referred to is provided with an operating electromagnet 15 which is adapted when successively energized to rotate a contact member 15 through the medium of a conventional type of ratcheting mechanism 15. contact member 15 is provided with a pair of electrically connected contact brushes, one for engaging a series of eight insulated contact buttons, and the other for engaging a series of eight .electrically connected contact buttons. The contact member 15 is adapted to move through a distance corre- The 18 clectromagnet 15 and normally open auxiliary contacts 15 are associated with the electromagnet 15.

The limit switch 17 is similar to the load switch 15 and the various parts thereof are designated by exponents corresponding to those used in the foregoing description of said load switch. One of the contacts carried by the contact member l7 cooperates with a series of five insulated contacts while the other contact carried by said member cooperates with a series of five electrically connected contacts. The auxiliary contacts associated with the limit switch 17 comprise normally open contacts 17 g associated with the operating electromagnet 17' and a normally open auxiliary switch 17 associated with the contact member 17. The switch 17 is adapted to close upon initial movement of the contact member 17 out of normal position.

The position switch hereinbefore referred to is provided with an} operating electromagnet 16 which is adapted to rotate a contact member 16 through the medium of a ratcheting mechanism 16 which is similar to that employed in the switches 15 and 17. The contact member 16 is provided with apair of contact brushes, one of which cooperates with a series of twenty-four equally spaced insulated contact buttons 16 and the otherof which engages a circular contact ring 16 The magnet 16 and its associated ratcheting mechanism 16 is adapted to move the contact member 16 in steps through distances corresponding to the spacing of the insulated contact buttons 16 and for purposes hereinafter set forth said magnet has normally open auxiliary contacts 16 associated therewith.

The selector switch 18 comprises a manually operated contact arm having electrically connected contact brushes, one of which is adapted toengage a series of nine insulated contact buttons 18, and the other of which is adapted to slide over a contact segment 17 The function and operation of the aforedescribed controller together with the circuit connections therefor will now be more fully described in connection with Fig. 2. It

.is assumed that theswitch 22 is in the posimoves the load switch contact element 15 in counterclockwise direction to position 1 and the same is held therein by its associated pawl. Upon response of the load switch the auxiliary contacts 15 associated therewith establish an energizing circuit for the closing coil of relay 11 extending from lineL to and through said auxiliary contacts, through the middle pole of switch 22,- through the closing coil 11 and through the auxiliary contacts 11 and switch 13 to line L Upon response of relay 11 the timing relay 10 is energized by acircuit-extending from line L through the right hand contacts 11 of relay 11, through the right hand down contacts 12 of relay 12, and thence through the operating winding 10 of the timing relay to line L However, upon closure of relay 11 relay 12 is also immediately energized by the circuit extending from line L through the right hand up contacts 11 of relay 11, through the operating winding 12, through the auxiliary contacts 12 of said relay, through the uppeqpole of switch 22, and through the zero position contacts of position switch 16 to line L Thus immediately upon establishment of the aforedescribed energizing circuit for the timing relay 10 the switch 12 responds to interrupt such energizing circuit whereby said timing relay remains in its normal position.

The relays 11 and 12 are now latched in their attracted positions, and when skip hoist bucket No 2 is brought into its load discharging position the switch 14 is closed.

Upon closure of switch 14 the load switch 15 is again operated one step, the winding thereof being energized by a circuit extending from line L through the auxiliary contacts 15 to and through operating winding 15, and thence through the left hand up contacts 11 and through switch 14 to line L The load switch is now moved to its second position and is held therein by its associated pawl I and the auxiliary contacts 15 of said load switch establish an energizing circuit for the trip coil 11 of relay 11, extending from line L through auxiliary contacts 15 through said trip coil 11 and thence through auxiliary contacts 11 of relay 11, and the switch 14 to line L. Upon tripping of relay 11 a circuit is again made for the timing relay 10, extending from line L through the righthand down contacts 11 of relay 11, through the right hand up contacts 12 of relay 12, and thence through the operating winding 10 of said timing relay to line L However, at this time a circuit is also made for the trip winding 12 of relay 12 extending from line L through the right hand down contacts 11 of relay 11, through the trip coil 12 of relay 12, through the auxiliary contacts 12 of said relay, and through the zero position contacts of position switch 16 to line L Upon tripping of the relay 12 the aforedescribed energizing circuit for the operating coil 10 of the timing relay is interrupted whereby said timing relay remains in normal position.

The aforedescribed operations are repeated until the number of loads determined by the setting of selector switch 18 have been dumped at the zero position. Assuming that the selector switch 18 is set in position four, when the fourth load is dumped the operation of the controller'is similar to that hereinbefore described in connection with closure of switch 14. However, load switch 15 has moved into its fourth position and, as soon as the operating magnet 15 of said switch and the relays 11 and 12 return to normal position the operating windingof the position switch 16 is energized to move said position switch to its degree point. This energiz-- ing circuitextends from line L through the right hand contacts 11 ofrelay 11, through the left hand contacts 12 of relay 1.2, through auxiliary contacts 15 of the load switch, through the operating winding 16 of the position switch, and through the selector switch 18 in its fourth position and the load switch 15 in a corresponding position to line L In this connection it should be noted that the aforedescribed energizing circuit is established in the same manner if the selected num-.

ber of loads is either six or eight. On the other hand, it should be noted that after dumping of either five or seven loads the relays 11 and 12 are latched in their at- I tracted positions. Thus if the selected number of loads is either five or seven the position switch 16 is energized through the medium of the right hand contacts 11 of relay 11 and the left hand contacts 12 of relay 12. Upon response of position switch 16 its associated contacts 16 establish an energizing circuit for the trip coil 15 of the load switch extending from line L through the right hand contacts 11 and the left hand contacts 12 or the right hand contacts 11", and the left hand contacts 12", as the case may be, through the auxiliary contacts 15 of the load switch and through the trip coil 15. and the auxiliary contacts 16 of the position switch to line L Trip coil 15 in respondin maintains itself through the medium of ts auxiliary contacts 15 which shunt the auxiliary contacts 16 of the position switch. The load switch 15 is then permitted to return mal position the same interrupts the aforedescribed energizing circuit for the operating winding l6 -of the position switch.

Assume now that the next load is delivered by skip bucket No. 1, the load switch 15 being in normal position and the position switch 16 being in its 60 degree position. Upon dumping of the load by skip bucket No. 1, switch 13 energizes the load switch 15 as hereinbefore described, moving the same to its first position. Upon response of said load switch the contact 15 thereof interrupts the atoredescribed maintaining circuit for the trip coil 15 and the pawl associated with said coil drops to normal position to prevent return movement of said load switch to normal position. Also as hereinbefore described, upon response of the load switch 15 the auxiliary contacts 15* thereof efiect response of relay 11 and said relay in turn establishes the aforedescribed energizing circuit for the 'olution, and as is apparent from timing relay 10. However, with the position switch on its 60 degree point relay 12 does not respond immediately since the aforedescribed energizing circuit for the said relay is opened by movement of the contact member 16 of the position switch out of its zero position. Thus the timing relay 1O responds against the action of its associated dash pot to connect the operating windings 1 and 2 of the line switches 1 and 2 across lines L L as is apparent from Fig. 2. Closure of said line switches connects motor M across lines L L through resistances R and R and thereafter the acceleratingswitches 3 and 4 operate in a well known manner to exclude said resistances from the motor circuit to bring the motor up to speed. The motor now operates until the hopper H is rotated through an angle of 60 degrees whereupon the rotary switch 19 makes one com lete revig. 2 the operating winding 17 of the limit switch is then connected across lines L L through the auxiliary contacts 11 of said limit switch. In responding limit switch 17 moves into its 60 degree position. The relay 12 is now energized by a circuit extending from line L through the right hand contacts 11 of relay 11, through the operating winding 12, through the auxiliary contacts 12", through the upper pole of switch 22 and thence through the position switch 16 which is in its 60 degree position and the limit switch 17 which is also in its 60 degree position to line L Response of relay 12 interrupts the aforede'scribed energizing circuit for the timing relay 10 and the latter relay in opening disconnects the windings 1 and 2 of the line switches from line L. However, the windings 1 and 2 remain connected to line L through the auxiliary contacts 17 9 associated with the limit switch 17 until the operating mechanism of said limit switch returns to normal position whereupon said contacts deing circuit for the limit switch operating winding 17 upon full movement of the hopper H through an angle of 60 degrees and said limit switch is then permitted to return to normal position since the trip coil 17 thereof is energized immediately upon response of relay 12. The energizing circuit for trip coil 17 d extends from line L through the right hand contacts 11 of relay 11 through the left hand contacts 12 of relay 12 and through said trip coil and the auxiliary contacts 17 associated with the contact element 17 to line L.

Assuming now that second load of material is dumped into the hopper H by skip bucket No. 2. As hereinbefore described switch 1 1 is then closed, which results in movement of the load switch 15 to its second position and tripping of the latching mechanism associated with the relay 11. The controller again operates in a manner similar to that above described to cause the motor M to rotate the load of material in the hopper through an angle of 60 degrees, except that now the timing relay 10 is energized through the medium of the right hand contacts 11 of relay 11 and the right hand contacts 12 of relay 12. Also, the timing relay 10 is now deenergized to stop the motor b tripping of relay 12. The tripping circuit or said relay is established from line L through the right hand contacts 11 of relay 11, through the tripping coil 12, through the auxiliary contacts 12 and through the position switch 16 which is in its 60 degree position and the limit switch 17 which is in a corre onding position to line L The aforedescrlbed operations are repeated until the number of loads determined by the setting of selector switch 18 have been dumped at the 60 degree point.

. Upon dumping of the selected number of loads at the 60 degree point the position switch 16 is again energized in the manner above described to move the same into its 120 degree position. With the position switch 16 in this position the controller opcrates in the same manner as when said switch was in its 60 degree position, exce t that now the motor is maintained energize until each load dumped into the hopper H is moved to 7 into its dumping position.

parent that when the selected number of loads have been moved to any of the dumping points the position switch 16 is advanced one step in a clockwise direction. Furthermore, it is apparent from the foregoing that the setting of position switch 16 determines the degree of operation of the motor Mupon other words, when the position switch 16 is in any position other than its zero position the motor M will operate upon dumping of each load into the hopper until the rotary switch 19 moves the limit switch 17 to a position corresponding to that of the position switch whereupon the relay 12 is operated as hereinbefore described to stop the motor.

For single bucket. operation of the skip hoist the double throw knife switch 22 is moved from the position shown in Fig. 1 into engagement with its left hand stationary contacts. Also, the operating mechanism for the limit switches 13 and 1 1 is arranged whereby switch 13 is closed upon lowering of the skip hoist bucket while switch 14 is closed upon movement of the skip hoist bucket Assuming that the parts of the controller are in the position shown in Fig. 1, upon lowering of the skip hoist bucket limit switch 13 is closed and establishes an energizing circuit for the operating coil 11 of relay 11 extending from line L through the middle pole of switch 22, through the operating winding 11, through the auxiliary contacts .11 and through said limitswitch to line -L Relay 11 in responding establishes an energizing circuit for relay 12 extending from line L through the right hand contacts 11, through the operating winding 12 of relay 12, through the auxiliary contacts 12 of said relay and thence through the upper pole of switch 22 to line L Relays 11 and 12 in responding are held in their operated positions by their associated latching mechanisms and the operating coils thereofare deenergized through opening of their associated auxiliary contacts 11 and 12. 1

Upon movement of the ski hoist bucket into its dumping position limit switch 14; is closed and establishes an energizing circuit for the loadswitch 15 extending from line L through the auxiliary contacts 15 of said load switch, through the operatin 15 thereof and through the left hand contacts 11 of relay 11 and the limit switch 14 to line L Upon response of load switch j15 the tripping coil 11 'of relay 11 is energized by a circuit extending. from line L through the auxiliary contacts 15 of the load switch, through the tripping coil 11 and through the'auxiliary contacts 11 and the limit switch 14 to line L Upon tripping of the'l'atching mechanism associated with relay 11 said relay returns to normal position and establishes an energizing circuit for winding,

ing relay 10 extending from line L through the right hand contacts 11 of relay 11,

through the right hand contacts 12 of relay tion immediately upon energization o the dumping of each load into the hopper. If? tlming relay 10 the trip coil 12 of relay 12 is energized b a circuit extending from line L through til relay 11, through the trip coil 11 and the auxiliary contacts 12 of the relay 12 and through the position switch 16 to line L 'Thuswith the position switch 16 in its zero position the energizin circuit for, the timing relay 10 is interrupte before the same can respond. I On the other hand, assuming position switch 16 is in a position other than its zero position, the timing relay 10 responds since the trip coil 12" can be energized only after the limit switch 17 hasbeen moved to a position corresponding to that of the position switch. The controller will thus operate in a manner similar to that hereinbefore described in connection with the double bucket operation thereof to provide for dumping of a selected number of loads into the furnace at six different points. i

In connection with the foregoing it should be noted that although the controller-is designed to provide for dumping of a selected number of loads at six equally spaced points the same can be readily modified to effect operations of said device through each of said ranges, said latter means including a e right hand contacts 11" ofv selector part adapted. .to be set in difi'erent positions for selection of the number of successive operations of said device through each of said ranges.

2. The combination with a rotatable hopper into which loads of material are discharged at a given point, of a motor for operating the same, control means for said motor including an element having different ositions to provide for difierent degrees 0 operation of said hopper by saidmotor, means a for operating said element in accordance with the number of loads of mate'rialdischarged into said hopper, said latter means including a selector device adapted to'be set in difl'erent positions to provide for selection of the number of loadsof material required to move said element into each of its different positions.

3. The combination with a rotatable hopper into which loads of material are dumped at a given point, of a motor for operating the same, means for starting said motor upon dumping of each load of material into saidhopper and for stopping the same after different predetermined ranges of operation of said hopper, said means including a control switch operable in a step by step manneroand having different positions to provide for different ranges of operation of said hopper, and means for operating said switch in accordance with the number of loads of material dumped into said hopper, said latter means including a device adapted to be set in difierent positions to provide for selection of the number of loads of material required to effect each step of operation of said switch.

4. The combination with a rotatable hop per into which loads of material are dumped at a given point, of a motor for operating the same, means for starting said motor upon dumping of each load of material into said hopper and for stopping the same after different predetermined ranges of operation of said hopper, said means including a control switch operable in a step by step manner and having different positions to rovide for different ranges of operation 0 said hopper, a second control switch operable in a step by step manner upon dumping of successive loads of material into' said hopper and adapted u on a plurality of successive operations to e ect a step of operation of said former switch, and means associated with said latter switch to select the number of operations thereof required to effect each step of operation of said former switch.

'5. The combination with a rotatable hopper into which loads of material are dumped at a given point, of a motor for operating the.

same, means for starting said motor upon dumping of each load into said hopper, said means includin a switch operable in a ste manner upon dumping of successive loa s into said hopper and means associated with said former means for effecting stopping of said motor. upon different predetermined ranges of operation of said hop er, said latter means including a control switch operable in a step by step manner and havin different positions to rovide for di erent ranges of operation 0 said motor, means as sociated with said former switch and adapted upon a plurality of successive operations thereof to effect a step of operation of said latter switch and means including a part.

adapted to be set in different positions for selection of-the number of operations of said of said devices being dependent for operation upon dumping of successive loads of material into said hopper and the other requiring a plurality of steps of operation ofthe former for each step of operation thereof, and means for effecting selection of the number of operations of said former element which are required to effect each step of operation of said latter element.

' 7. The combination with a movable distributing device and a drive therefor, of means for controlling said drive to effect successive operations of said distributing device through each of a plurality of difierent ranges, said means including means for automatically changing the range of operation of said distributing device upon a se- 7 means for controlling said drive to effect successive operations of said distributing device through each of a plurality of different ranges, said means including a control device movable into different positions for selection of the range of operation of said distributing device, means for automatically changing the position of said control device upon a selected number of successive operations of said distributing device through each of said ranges, and means for effecting selec-. tion of the number of successive operations of said device through each of said ranges.

In witness whereof, I have hereunto subscribed my name.

NIELS L. MORTENSEN.

latter switch which are required to efiect a single step of operation of said former switch.- 1 I 6. The combination with a rotatable dis- 

